Press-welded flexible connectors made of copper laminations (PE) are among the products most often ordered for connecting high-current systems and absorbing vibration. Together with PG connectors made of flat copper braid, they are the basis of all connections in the power industry.
Press-welded, riveted or welded?
Making flexible connectors is a niche business that serves engineering firms in the power sector. Equipping such a plant is a challenge, because the machines are designed for a specific manufacturer.
We have been making connectors since 2000 and have used various methods over the years. Connectors made of copper laminations can be produced by:
- riveting: holes are drilled at the ends of the connector, copper rivets are inserted and pressed;
- welding the ends: a copper flat bar of suitable thickness is welded to each end of the lamination stack; it forms the terminal and holds the laminations together;
- press welding: the copper laminations are joined on a resistance welding machine using a high current.
Press welding is clearly the best option for quality and speed, but it requires the right welding machines and plenty of electrical power at the plant.
What does press welding do?
Under a high current and the pressure of the press, the copper bonds into a single piece that, at the ends of the connector, looks just like a flat bar.
A connector made this way combines two advantages: it is flexible, yet rigid at the ends like a flat bar. It can be used wherever the connector does not need to move in several directions. Copper laminations naturally allow less movement than a comparable connector made of flat copper braid.
What are PE flexible connectors made of?
Flexible connectors use copper laminations 0.2 to 0.5 mm thick, stacked to the required cross-section and then joined. They are made of Cu-ETP copper, usually half-hard or soft.
It is worth considering the temper of the material: soft copper is not springy, so the connector will give easily and change its shape.
The laminations are usually joined on a resistance welding machine fitted with a hydraulic press and graphite electrodes. At IZAR we use high-power welding machines that can join connectors with large cross-sections.
Press welding is not an option for similar connectors made of aluminium laminations: aluminium is covered with an oxide layer that prevents the laminations from bonding into one piece. They can only be riveted or welded.
We usually match the width of a laminated copper connector to the terminal and its thickness to the current rating. The current rating table is on our website, and for non-standard enquiries we help to calculate the right cross-section.
Can laminated copper connectors be tin- or silver-plated?
Yes. Press-welded connectors can be tin- or silver-plated to suit the project. The coating is applied by electroplating.
What shapes are possible?
Unlike flat braided connectors, laminated copper connectors are formed during production. As standard they can be bent at the terminal, but profiled connectors like the ones in the photo below are also very popular.
What are the advantages of press-welded connectors?
First of all, they cost somewhat less than PG connectors made of flat copper braid, which matters a lot in large volumes.
For the same cross-section, their terminals are about 40% thinner, so they work well where there is little space for the connector (rigid terminals close together).
They behave more stably under short-circuit currents. Their surface can be electroplated and can also be painted with paints made for this purpose.
These connectors are very durable, but less flexible than braided connectors. The choice is up to the designer.
To find out more about PE laminated copper flexible connectors, use our contact form or call +48 71 303 62 09 and talk to our expert about what these connectors can do.
Would you like a quotation or the current rating for your connector? Send your enquiry to biuro@izar.pl.
